Life-raft



J. F. Twice.

LIFE RAFT. APPLICATION FILED DEC.6, I918- 1,336,872. 7 Patented Apr. 13,1920.

H} N o f a o 1s. J

r H a a A I f Ei:i w w T r s i ATTORNEYS JOHN F. TWIGG, OF SANFRANCISCO, CALIFORNIA.

LIFE-RAFT.

Specification of Letters Patent. Patented A131. 13, 1920.

Application filed December e, 1918. Serial No. 265,513.

To all whom it may concern:

Be it known that I, JOHN F. TWIGG, a citizen of the United States,residing at the city and county of San Francisco and State ofCalifornia, have invented new and-useful Improvements in Life-Rafts, ofwhich the following is a specification.

This invention-relates to a life raft, and particularly to improvementsonthe catamaran type oflife raft now usually car ried by sea-goingvessels.

One of the objects of the present invention is to provide a life raftwhich is economical and substantial in construction and .so designed asto be readily disassembled for inspection, repairs, repainting, etc.,and also to permit two or more rafts to be stacked one on top of anotherin the least space possible.

Another object of the invention is to provide a raft consisting of arigid wooden frame buoyed up or supported by a plurality of cylindersarranged on each side of the frame, which cylinders may be inspectedfrom all sides and individually repaired or replaced without disturbanceto the balance of the structure or tanks. Another object of theinvention is to provide a raft which permits a standardized constructionregardless of the capacity required, that is, the same frame and tanksare used when building an eighteen-person raft as would be em ployed inthe construction of a twelve-person raft. The only difference would be alengthening ofthe frame to permit addition of the required number oftanks. Another object of the invention is to provide a structure whichpermits reversing of the raft and which also permits foldable coamingsections to be employed on either side, as will. hereinafter bedescribed. Further objects will hereinafter appear.

The invention consists of the parts and the construction, combinationand arrangement of parts as hereinafter more fully described andclaimed, having reference to the accompanying drawings, in which Figure1 is a plan view of the raft, partly broken away.

Fig. 2 is an end view of the raft.

Referring to the drawings in detail, A indicates in general theframework of the raft and B the tanks by which it is buoyed up orsupported. The detailed construction of the raft shows that it consistsof a pair of longitudinal bulk ead members 2. which are tied together byop and bottom rails and 4; respectively extending crosswise of thebulkhead frames and rigidly secured thereto, each rail being mortised toform a perfect interlock with the longitudinal bulkhead frames.

The frame further consists of top and bottom flooring, such as shown at5 and 6, and of inner and outer end stiles, as shown at 7 and 8, whichare secured in position by means of bolts 9, each of which is providedwith turn buckles 10. Extending from end to end of the frame is a pairof fender rails 11, which further increase the strength of the frame,and interposed between said fender rails and thelongitudinal bulkheadframes 2 are the tanks B. By referring to Fig. 1 it will be seen that aplurality are employed on each side. Each tank is disposed between thetop and bottom. rails and the fender and longitudinal bulkhead frames.They are locked against endwise movement by the top and bottom rails andare otherwise held against displacement by the fender rails 11. Theindividual tanks are thus freely supported within the frame and do notform any part thereof, their only function being that of buoying up orsupporting the frame.

For the purpose of presenting a flat surface on each side to permitstacking of rafts on board ship in as compact a space as possible, Iprovide foldable coaming sections, such as shown at 12 and 13. Thesections 13 form the end coamings and the sections 12 the side coamings.All coaming sections are secured to the frame by means of hinges 14 andeach coaming section may be locked whether raised or lowered by means ofhooks 15. The row locks may be secured directly to the coaming sectionsor may be inserted therein whenever required, ordinary row lock sockets16 being provided for this purpose. The raft may otherwise be equippedwith-straps, such as shown at 18, to permit the oars to be clamped orlashed to the sides of the raft and it may also be provided with ringsat each end, shown at 18, to permit the rafts to be easily handled whenthey are stacked or swung overboard. The space formed between the floorsections 5 and 6 may, in this instance, be employed for the storin ofvarious articles, such as a bread tank 20, water tank 21, ditty box 22,

sea anchor 24:, and, in fact, anything required or useful.

The usual catamaran life rafts heretofore employed consist of two longbuoyant cyl-- inders constructed of galvanized iron and divided intocompartments by bulkheads, each water-tight from the other and the sea.In practice, it is found that handling, contraction and expansion of themetals, etc. often cause leaks from one compartment to another, in whichcase it is an expensive, and, in most instances, impractical job torepair, as the cylinders must be taken apart to reach the inside injury.This defect has been entirely overcome in the present instance, as aplurality of cylinders are employed which may be inspected from allsides and individually repaired or removed without disturbing thestructure or the remaining tanks. Again, it should be obvious that thecost 'of replacing tanks such as here shown cannot be compared with thatof a large catamaran cylinder.

The ordinary catamaran raft depends more or less on the strength andrigidity of the buoyant cylinders for the rigidity of the wholestructure. Therefore any excessive strain put on the raft as a wholeplaces a stress on the cylinders which may cause a fault or leak ofcompartments. An advantage of the present construction is the provisionof the rigid frame in which the tanks are freely mounted, therebyrelieving the same of twisting or other strains which always occur inthe main frame. The tanks in this instance are only subject to buoyantstresses, and, as the frame is almost entirely constructed of wood asagainst steel and iron of the common raft, the added buoyancy increasesthe efficiency.

Often aboard ships space for carrying life saving equipment is limited,and it is therefore always desirable to carry one or more rafts on topof the other. The usual design of raft makes this rather impracticable,as the construction does not safely permit piling or nesting of two ormore rafts as the height becomes too great. The present structureprovides that the coamings or bulwarks of the rafts are hung on hingeson both top and bottom of the raft so that they may be laid down flushwith the decks, hence reducing the height aboard ship to a considerableextent and leaving a flat substantial surface that permits stacking ofat least two, if not three, rafts.

The average catamaran life raft is designed especially for the capacityof a given number of persons. The same structure or cylinders are notsuitable for a greater capacity; hence, twelve-person, fifteen-person,eighteen-person rafts, etc., are each of a special and varying design.My construction provides an expansive or extensible design, that is,comparatively little change is required when it is desired to increaseor decrease the capacity of a raft. If twelvep erson rafts are beingconstructed and it is desired to build an eighteen-person raft, itshould be obvious that it will only be necessary to lengthen the frameso that additional cylinders may be added to increase the buoyancy ofthe raft.

The present drawing shows a twelve-person raft, that is, each pair ofcylinders is intended for three persons. Therefore if an eighteen-personraft is being constructed, it will only be necessary to add two pairs,or four more cylinders, and to increase the length of the framecorrespondingly. The detailed construction and the height or width ofthe raft is not changed.

While certain specific arrangements in construction are here shown, Iwish it imderstood that such features may be varied; similarly, that thematerials and finish of the several parts employed may be such as theexperience and judgment of the manufacturer may dictate.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A life raft comprising a pair of longitudinal bulkhead frames, topand bottom rails extending crosswise thereof and .secured to the same, aplurality of tanks arranged on the exterior side of each bulkhead frame,and means for securing the tanks against endwise and lateral removal.

2. A life raft comprising a pair of longitudinal bulkhead frames, topand bottom rails extending crosswise thereof and secured to the same, aplurality of tanks arranged on the exterior side of each bulkhead frame,means securing said tanks against lateral movement, said means com-vprising guard rails extending from end to end of the frame.

3". A life raft comprising a pair of longitudinal bulkhead frames, topand bottom rails extending crosswise thereof and secured to the same, aplurality of tanks arranged on each side of the bulkhead frames, meanssecuring said tanks against endwise and lateral movement, said meanscomprising guard rails extending from end to end of the frame andsecuring the tanks against lateral movement, cross rails securing thetanks against endwise movement, and a top and bottom platform secured tothe cross rails and also securing the tanks against upward or downwardmovement.

4. A life raft comprising a pair of longitudinal bulkhead frames, topand bottom rails extending crosswise thereof and secured to the same, aplurality of tanks arranged on the exterior side of bulkhead frames, arail on each side of the raft exterior of the tanks, adapted to protectand secure the tanks against lateral removal, a top and bottom platformsecured to the cross rails and also securing the tanks against upwardand downward movement, foldable coaming sections secured to the crossrails, and means In testimony whereof I have hereunto set for securingsaid coaming sections both in my hand in the presence of two subscribingtheir IiLlSGd and 1n their folded posltlons, Witnesses.

said coaming sections adapted to lie flush JOHN F. TWIGG. 5 with the topand bottom platforms When Witnesses:

folded to permit stacking of one raft upon W. W. HEALEY,

the other. M. E. EWING.

